MYASO

Meet Yet Another Shellcode Obfuscator!

Evade AV by hiding cmd/shellcode/... payloads inside images and simply running them.

Installation

Linux

apt update
apt install -y gcc libc-dev g++-mingw-w64-i686 g++-mingw-w64-x86-64 libgdiplus mono-devel golang-go
git clone https://github.com/adeadfed/myaso
cd myaso
pip3 install -r requirements.txt

Docker

git clone https://github.com/adeadfed/myaso
cd myaso
docker build -t myaso:latest .

Usage

Generate image

myaso embed -a sc.bin [-i image.bmp] [-a <algorithm>] -o evil_image.bmp

In Docker:

docker run --rm -it -v `pwd`:/mnt/ myaso embed -f /mnt/your_shellcode.bin -o /mnt/stego.png -a LSB

Generate runner

myaso bake

You will be asked all the details interactively. At the end you'll be offered to save the configuration, which you can then use with:

myaso bake [--def saved_definition.yml]

[banner]

? Desired stego algorithm:  LSB
? Desired runner language:  C++
? Desired runner arch:  x64
? Desired payload type:  Shellcode
? Desired image source:  (Use arrow keys)
 ❯ ImageFile
   HTTPX
  ...

In Docker:

docker run --rm -it -v `pwd`:/mnt/ myaso bake

(Set output to your mount dir!)

[banner]

? Desired stego algorithm:  LSB
...
? Output runner file:  /mnt/your_runner.exe
? Save config to file?  Yes
? Location:  /mnt/your_config.yml

Execute shellcode

c:\> reader.exe happy_cat.bmp PAYLOAD_BYTES

Feature support

Supported stego algorithms:

Algorithm	C++	C#	Go	PS	VBA
LSB	✓	✓	✓	✓	✓
LSBX	✓	✓	✓	✓	✓
LSBM	✓	✓	✓	✓	✓
ColorCode	✓	✓	✓	✓	✓

Supported payload types:

Payload	C++	C#	Go	PS	VBA
CMD	✓	✓	✓	✓	✓
Shellcode	✓	✓	✓	✓	✓
PE	WIP

Supported image formats:

Image format	C++	C#	Go	PS	VBA
PNG	✓	✓	✓	✓
BMP	✓	✓	✓	✓	✓
JPEG

Supported payload delivery methods:

Payload delivery	C++	C#	Go	PS	VBA
HTTP	✓	✓	✓	✓
Local file	✓	✓	✓	✓
Document					✓

Notes

roadmap

Is it any good?

yes.